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Port 6961 (jmact3)

IANA assigns port 6961 to jmact3: JMACT3.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
jmact3 TCP JMACT3 Yutaka Ono -
jmact3 UDP JMACT3 Yutaka Ono -

Check what is listening on port 6961

Linux: is anything listening on TCP 6961?
sudo ss -tlnp 'sport = :6961'
Linux: UDP 6961
sudo ss -ulnp 'sport = :6961'
Linux / macOS: which process owns the port
sudo lsof -nP -i :6961
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':6961 '
Windows (Command Prompt)
netstat -ano | findstr :6961
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 6961 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 6961
From Windows
Test-NetConnection HOST -Port 6961
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 6961

Block port 6961 in the firewall

ufw
sudo ufw deny 6961/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 6961 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 6961 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 6961' -Direction Inbound -Protocol TCP -LocalPort 6961 -Action Block
ufw
sudo ufw deny 6961/udp
iptables
sudo iptables -A INPUT -p udp --dport 6961 -j DROP
nftables
sudo nft add rule inet filter input udp dport 6961 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 6961' -Direction Inbound -Protocol UDP -LocalPort 6961 -Action Block

Related ports

6946bioserver6951otlp6962jmevt26963swismgr1

All port numbers · Open port checker
Assignment data: IANA port number registry (public domain), retrieved 2026-11-10.